The present invention relates to a distributed control system, in particular for implementing an automation system. Furthermore, the present invention relates to a system component for such a distributed control system.
German Patent DE 196 24 929 A1 discloses a distributed control system, in which sensors and actuators are connected to a configuration unit via a bus system. Therein, the bus system is configured as a communications channel. In the configuration unit, an operating and monitoring interface is generated. In this reference, several possibilities for configuring and operating the distributed control system are described. A technically simple but costly and unreliable option is to program the system components individually and to generate, separately therefrom, a layout plan by means of the configuration unit. This layout plan includes information on the function and the position of the components within the system. To reduce the programming cost, the reference proposes to provide each of the system components with a memory, which stores component-specific data. In this memory, the corresponding function of the system components, such as controllers, and their integration into the automation system, can be stored. The integration of a component into the automation system is described by the addresses of other system components, with which the respective component interacts. In the case of a controller, these addresses are the addresses of the setpoint generator and the actual value sensor from which the controller receives its input values. Furthermore, these addresses include the address of the actuator, which is controlled by the controller. This component-specific data is transmitted from the system components to the configuration unit via the data bus. Based on this data, the configuration unit automatically generates an operating and monitoring interface. A drawback of this option is that the programming of the individual system components is relatively costly.
U.S. Pat. No. 5,519,878 proposes another distributed control system. To implement the distributed control system, a configuration unit requests a unique identifier for a system component prior to installation of that system component. This unique identifier is printed on an adhesive label as a barcode, which is then, on site, affixed on a layout plan at the position of the system component. This layout plan is in paper form and reflects the spatial positions of the system components within the system. The configuration unit is equipped with a display screen to display the layout plan and with a reading device to automatically read in the barcode. The barcode, which reflects the unique identifier of a system component, is automatically read in by the reading device, and is, based on the displayed layout plan, assigned to the corresponding position of the system component in the graphic display. The identifiers of the individual system components are used to configure a network, which interconnects the system components for data transmission purposes. The drawback is that affixing the adhesive labels to the paper layout plan and assigning the unique identifiers to the individual system components on the display screen must be done manually. Therefore, this method is subject to errors.